1. Technical Field of the Invention
The present invention relates in general to the telecommunications field and, in particular, to a method and system for handling interactions between telephone subscriber services.
2. Description of Related Art
Many new supplementary subscriber services are being introduced into today's telephone networks. However, it has become an increasingly complex process to handle interactions between different subscriber services, since no undesired behavior resulting from the interactions can be tolerated. Consequently, in order to minimize such interactions, different nodes are used to handle supplementary services in existing communication networks. As such, a need has arisen to be able to handle these interactions between services in a much more flexible manner.
Currently, interaction handling functions are distributed across all of the software modules that process the services concerned. In most cases, the interaction handling functions are hard-coded in these software modules. Consequently, in each of these software modules, an interaction decision has to be made whenever a service is to be activated or deactivated.
A significant problem with interaction handling in existing telephony systems is that the undesired behavior that occurs contradicts the original intention of the services involved. Typically, this problem is caused by the different services interacting with each other in many undesired or unpredictable ways. Obviously, this undesirable behavior should be avoided whenever possible.
One approach used to avoid such undesirable behavior is to control the activation and deactivation of the services. In this regard, the technical specifications for these services define how to avoid this behavior, by not allowing the services that can cause the undesired behavior to be activated at the same time. For example, the technical specifications for the Global System for Mobile Communications (GSM) define more than two hundred such service interactions. As such, the service interaction handling functions have to be performed when the defined services are activated or deactivated, or when a mobile communication system subscriber roams from one country to another.
The most significant problems with existing service interaction handling approaches arise when the software being used to perform the interaction handling functions moves into the sustaining phase. If this software is designed to function in the traditional manner (i.e., distributed to all the software modules dealing with the services involved), the following problems arise: (1) It is very difficult to obtain a general overview of the services that will interact, which makes it time-consuming and costly to train designers in this field; (2) It is also very difficult to make changes to the services that will interact; and (3) It is also very difficult to add new services that will interact with the existing services. However, as described below, the present invention successfully resolves these problems.